Referring to FIG. 1, a typical camera module 1 includes a lens barrel 2, a lens holder 3, an image sensor 4 and a circuit board 5. The lens barrel 2 receives at least a lens therein and disposes an outer screw thread 6 on an outer surface thereof. The lens holder 3 defines a compartment and disposes an inner screw thread 7. The inner screw thread 7 is a counterpart of the outer screw thread 6 to cooperatively engage the lens barrel 2 to a first end of the lens holder 3. The image sensor 4 is affixed onto the circuit board 5 by surface mount technology (SMT). The circuit board 5 is attached to a second end of the lens holder 3 and thus the image sensor 4 is received inside the lens holder 3.
However, due to limited precision in manufacturing, the central axis A1 of the image sensor 4 is not parallel to the central axis A2 of the camera module 1. Accordingly, images captured by the camera module 1 will be distorted.